Collapsible conduit



July 4, 1944. l.. l.. wlLsoN COLLAPSIBLE CONDUIT Filed .my 25, 1942 WITN Patented July 4, 1944 COLLAPSIBLE CONDUIT Ladd-L. Wilson, Oxford, Ohio, assigner to Norristown Magnesia dav Asbestos Oo., Plymouth, Borough of Norristown, Pa., a corporation of Pennsylvania Application July 25, 1942, Serial No. 452,361 a claims. y(o1. 1st-5s) .ff This invention has general reference to means forpconducting gaseous substance from a source of=.supply for .use and distribution as desired; While'- it pertains, more particularly to a novel conduitor vservice connection for'warm-air heating appliances for installation in houses, factory buildings, drying'rooms and so forth. Heretoforethe atmospheric air warmed by heater of the` type referred to has been conducted from said heater. through sheet-metal piping functional as heating means rather than as flues. However with the prevailing priority on, and extremely limited available supply of, sheet metal for the fabrication'of` piping, the related manufacturing art has. become seriously impaired. Another disadvantage inhering. to the production and use of sheet metal piping, not' only in connection with heating apparatus, but in kindred arts where such-piping has superseded cast metal piping, is the4 comparatively large space involved for packing and shipping said piping in bulk.

VA primary aim of the present invention is to overcomethe above specified impairment and disadvantage in a ysimple and economical manner, by respectively'making use of va novel substitute for the' sheet metal whereby a saving of approximately 95% in metal is effected; and by the provision of a highly durable conduit capable of compact collapse for package and shipment with resultant considerable saving in overhead and shipment costs,

Another aim of this invention is to provide conduit of the species indicated of differential dimensions with associated connectors, by the use of which the adjoining ends of such conduit may be coupled in substantial abutment, and installations of the conduit made without any juncture ange or union projections.

A further aim of this invention is to furnish collapsible conduit well adapted to plenum systems of ventilation wherein heated-air is forced by artificial means and the vitiated air removed by displacement.

A still further aim of this invention is the provision of collapsible conduit having associated connector elements which, when aligned and assembled, with the junctures sealed, will present a substantially smooth and rigid structure.

Yet another aim of the present improvements is to furnish conduit rof the above indicated species which readily lends itself to subdivision and branching for take-off of the heated air at desirable levels and in different directions.

With the stated aims and auxiliary advantages in view, this invention consists essentially in the hereinafter fully described. Y

fabrication of conduit from fire-resistant corrugate board, creased to define the desired crosssection: of piping, in combination with corresponding section insert connectors having a sur-` rounding medially-located thinrfiiange Yor fin for snug Vabutment by the adjoining ends of aligned lengths of said conduit 'substantially as hereinafter disclosed, typically illustrated by the accompanying sheet of drawings forming a part oi? this specification, and more particularly defined in theconcluding claims.

In the drawing;

Fig. 1 is a broken elevation of a portion of a hot-air piping system embodying the present lnvention. I,

Fig. 2 is anv enlarged detail section taken approximately as indicated by 'theV angle-arrows II--II in Fig. 1.

Fig. 3 is an'end view of one of vthe conduit sections collapsed for packing and shipment; and,

Y Fig. 4 is a perspective View of a connector unit In describing the embodiment of this invention, typified by the above captioned figures, specicterrns'will be employed for the sake of clarity, but it is to be understood the scope of said invention is not thereby limited; each such term being intended to embrace all equivalents which perform the same function for an analogous purpose.

Referring more in detail to the drawing the numeral 5 conveniently designates the plenum and 6 superposed conduit sections, while 1 indicates a relatively smaller continuation, all of which are individually fabricated in accordance with the invention.

Each conduit section 5, 6 and 'l is preferably fabricated from a sheet of corrugated strawboard 8, Figs, 2 and 3, severed tothe desired size, and creased along paralleling lines so that, when bent therealong, said sheet conveniently denes arectangular-section pipe of the required size embodying opposed walls 9, l0, and an overlap or seam Il for securement as by carton staples l2. Particular attention is directed to the fact that the strawboard 8, in accordance with this invention is coated on both planar faces, prior to severance to the desired sizes kfor formation of the conduits or pipes 5, 6 and 1, with an integrated reproofng substance, such as asbestos, to provide an inner and an outer protective strata or covering I3, I4 respectively. Furthermore such protective covering i3, I4 may be rendered moisture-proof in any of the well known ways, if deemed desirable or expedient.

Conduit or pipe sections 5, 6 and 1, are arranged in end to end alignment and held tgether by thin suitable material, such as galvanized sheet-metal connectors I5, one of which is shown in perspective in Fig. 4. Each such connector I is of a shape conformatory to the bore of the conduit sections 5, 6 or 1 with which it is to be used, While it embodies minor paralleling walls I6 and major walls Il respectively for snug coaction with the conduit walls 9, I0, in an obvious manner. Substantially surrounding the connector and medially exterior thereto are lat.-

erally projecting flanges I3 of a Width not eX- ceeding the thickness of the strawboard 8, said flanges conveniently consisting of galvanized sheet-metal angles I9 rigidly secured to the connector I5 as by tack welds 20; or, such anges dent; while it is to be expressly understood that the cross-section of the plenum 5, conduit sections 6 and 1, as Well as the take-off branches 2l. 26, an upper extension 29, Fig. 1, and the connectors I 5 and 28 may be of other than rectangular cross-section, such as regular or irregular polygonal shape, Without departure from the fundamentals of this invention. Furthermore, it is herein emphasized that the saving of sheet metal effected by this invention is clearly very jconsiderable; while the instant improvements might be formed integral with said connector without departure from the spirit and scope of.

between the adjoining ends the resultant junc-l ture is, preferably, secured by means of appropri.

ate screws 2| driven through the straw-board 8 into registering holes 22 to each side of the angles i9 in an obvious manner; whereupon the conduit closely adjoining ends, as well as the heads 23 of said screws 2|, may be sealed by an overlapping strip of adhesive material 24. Now it will be self-evident the joint so formed is not only rigidii'led in a very simple and eflicient manner, but that such joint is sealed against any possibility of leakage from the interior outwards.

i. For take-off branches 25, 26 appropriate elbow 2l, with mating connectors 28 are tted at different levels; for instance in combination with the-lower and upper end of the broken section 1, it being understood the respective parts are properly proportioned for snug coactive interengagement, and that all of such joints are preferably sealed by adhesive strip 24, as before described.

From the foregoing it is thought the merits and advantages of this invention Will be self-evifurnish al serviceable and durable substitute conduit for sheet-metal pipe in hot-air heating .apparatus and the like, which is also compactly terial insert connector device, having a medially.v located surrounding fin, in Width not exceeding' the thickness of the ber board, rigidly coupling the adjoining ends of aligned lengths of such conduit without exterior projection; and

means for attaching the adjoining ends of thev conduit to the insert connector. 2; Conduit in accordance with claim 1 wherein the insert connector is provided with a substan-- tially surrounding medially-located fin of a width4 approximating the thickness of the corrugate' sheet iron; similar material angles are perma' nently attached to the connector to define coplanar flanges, projecting medially outwardsv therefrom; and appropriate screws attach the acl'-y joining conduit ends to the connector.

LADD L. WiLsoN. 

